Filling arrangement for subterranean storage tanks

ABSTRACT

A fill pipe for a subterranean storage tank has a hydraulic jump therein, near the bottom of the pipe and near the bottom of the tank, to absorb a portion of the kinetic energy of the falling liquid. The fill pipe has a smaller pipe therein, to enable removal of water from the tank floor.

O Unitedv States Patent [1113,552,435

[72] Inventors Craig R. Anderson 56] R f e Cited East Liverpool, Ohio; Albert Thomas Olenzak, Media, Pa. UNITED STATES PATENTS 1,042,107 10/1912 Grant 220/85 [21] 1 App1.No. 780,804

2,123,809 7/1938 Sertz 137/592 [22] Filed Dec. 3, 1968 2,294,] 76 8/1942 Gredell 220/86 [45] Patented Jan. 5, 1971 [73] Assign Sun on Company 2,310,450 2/1943 Longdin 220/86 Philadelphia, Pa. Primary Examiner-William R. Cline a corporation of New Jersey Attorneys-George L. Church, Donald R. Johnson, Wilmer E.

McCorquodale', Jr. and Frank A. Rechif [54] FILLING ARRANGEMENT FOR SUBTERRANEAN STORAGE TANKS 4 Clain'as, 5 Drawing Figs.

[52] U.S. Cl 137/592,

i 220/85 ABSTRACT: A fill pipe for a subterranean storage tank has a [5]] Int. Cl ..Fl7c 13/00, hydraulic jump therein, near the bottom of the pipe and near 865d 25/02 the bottom of the tank, to absorb a portion of the kinetic ener- 5 0] Field of Search 137/590, gy of the falling liquid. The fill pipe has a smaller pipe therein,

- to enable removal of water from the tank floor.

(3) rain leaking into the fill tubes of service station storage FILLING ARRANGEMENT non SUBTERRANEAN Y STORAGETANKS This invention relates to a filling arrangement for subterranean storage tanks, such as the tanks commonly used at ser- 5 vice station operator and the motorist a great deal of trouble l0 and inconvenience. Dirt can clog the small jets in modern carburetors and can also clogfuel linefilters. Water can cause rust, corrosion, fuel line freezeups, and, if it; comes in slugs, can cause an engine to stop. This can lead todollar cost liabilities, borne by the oil company, for repairs,'andalso to loss of customer goodwill. Also, water may freeze'in the service station gasoline pumps, which is a great inconvenienceto the service station operator. 4 i r The problem of dirt has been attacked by: installing filters, capable of removing very fine'parti'cles, ahead of the gasoline pump nozzle.

Reducing the water contamination is a much more difficult problem. Cleanliness is a big help, but the problem cannot be solved by this alone. Water gets into the fuel in service station storage tanks in many ways, some of which are:' (l) the floating roofs on large storage tanks at the refinerymay leak'rain water, the water in these tanks then being conveyed by tank trucks to service stations and delivered into theservice station storage tanks; (2) breathing of service station storage tanks;

tanks.

Chemical or physicaldrying of the gasoline stream just prior to its entry into the customer's"automobile-gasoline tank is technically possible. Drying apparatus using "molecular sieves,

activated alumina, etc., will do a very thorouigh job, but such apparatus is currently very costly, and also inconvenient. This apparatus is too expensive to use without regeneration, and regeneration presents an almost insurmountable logistics problem.

particularly acute just after a load of gasoline is delivered to the service station storage tank. The mixing action of the falling fuel on the layer of water and dirt usually present 'at the bottom of the subterranean storage tank causes these contaminants to become dispersed in the fuel,

The present invention, in its broadest aspects, contemplates. reducing the amount of energy available for mixing at the time the fuel is delivered to. the subterranean storage tank, that is,

at the time the service station storage tank is filled. This, along 0,

terranean liquid fuel storage tanks characterized, in that: it

functions to reduce the mixing of water, dirt, and fuel during the tank-filling operation.

A further object is to providf, a, device of the aforesaid character whichrcan be applied totanks. already inservice,..as well as to new-tanks. t

An additionalobject is to-pro'videa d'eyiccof'the' foregoing character which is inexpensive toconstructand' install A still furtherobjectis to-provide a filling arrangement. for

subterranean liquid" fuel storage tanks which has incorporated therein a facility. which-allows waterto be removed from the tank floor. I

The objects of this invention are-accomplished, briefly, in

the following manner: A; fill pipeextends from the surface:

down to the topiof' a-subterranean .liquidifuel storage tank, and thence through the interior of this tank to the bottom thereof. The fill pipe is coupledto'the interior'of the-tanknear-th'e bottom thereof but somewhatxabove the.same,thiscoupling-com- (illustrated as a pivoted closure 6).

liquid, to change" its direction of flow as it leaves the fill pipe I and passes to the tank interior. A smaller pipe is mounted concentrically within the fill pipe and is open to the tank interior only at a location closely adjacent the bottom of the tank; this smaller pipe extends upwardly to the surface.

A detailed description of the invention follows, taken in conjunction with the accompanying drawing, wherein:

H0. 1 is a somewhat diagrammatic vertical sectional view, with a portion thereof broken away, of a subterranean storage tank equipped with a filling arrangement according to the invention; V a

FIG. 2 is a fragmentary vertical section, on an enlarged scale, of theupper portion of the filling arrangement;-

FIG. 3 is a fragmentary section, on an enlarged scale, of the portion of the filling arrangement included in the dot-dash rectangle labeledFlG. 3-- in FIG. 1;

FIG. 4'is a sectional view taken along line 4-4 in F l6. 3; an

FIG. 5 is a sectional view taken along line 5-5 in FIG. 3.

Referring now to the drawing, numeral 1 denotes a subterranean storage tank, of the type customarily used at service stations for the storage of liquid fuel (gasoline). This tank is provided with the usual vent and discharge or dispensing lines (not shown), and is located below the surface or grade 2. A continuous fill pipe 3 extends substantially vertically from the surface 2 (actually, from a point slightly above the surface) to the top of tank 1. Pipe 3 is sealed at 4 through the top of tank 1, and continues downwardly, substantially vertically, through the-interior of the tank 1 to the bottom 5 thereof, that is, to the tank floor. v i 1 I The upper end of pipe 3, at or slightly above the surface 2, is closed by a removable fill cap of conventional construction The lower end of pipe 3 is closed by means of a substantially imperforate hollow frustoconical member 7, resembling somewhat an inverted funnel, to the outer conical surface of which the lower 'end of pipe 3 is sealed, as by welding. Member 7 will be referred to further hereinafter.

Near the bottom 5 of the tank, but somewhat above the The problem of contamination (both l at r and dm) IS same, the fill pipe 31s coupled to the interior of tank 1, to ena ble liquid to flow from the fill pipe into the tank interior. This coupling employs a hydraulic jump arrangement denoted generally by numeral 8 The arrangement 8 comprises a; plurality of spaced horizontally extending apertures '9 which are drilled in approximately radial directions through the wall of pipe 3, and also a diverting or deflecting means 10; the means 10 consists of a shield member fixed to the outside of pipe 3, just below the apertures 9, having an upwardly extending wall at its outer periphery such asto deflect or divert the liquid is.- suing through the apertures9 upwardly, or away from the tank bottom 5 I The hydraulic jump arrangement 8', comprising the apertures 9 and d-ivertermeans. 1'0 acting in combination, serves to change the directionbf'flow' of the liquid which is flowing (essentially falling) down the fill pipe 3. That is to say, thedirection of flow isaessentially reversed (from downwardly, inv pipe 3, to upwardly,.as the liquid fl'eaves diverter means 1'0) This reversal ofth'e fl'ow actsto absorb a portion of the energy of the falling liquid, which is to say that much of the'kinetic energy of the dropis. converted into mechanical energy loss',-

byv way of turbulence: and-viscous friction- As a: result of'this loss ofienergy,.theenergy-availablerfor mixing' of't'he new fuel being delivered into tank 1 with the layer of'water and. dirt" usualliypresent at'ithe bottom: 5 .of the ta'nl'c ('Li.e.,.the. mixingat the time. the'tank 1v is bei'ng. filled, by way of'th'e fill pipe 3 ),.is appreciably reduced;.t herefore,. such mixing, and'tl'ie' resulting contamination,.areconsiderably reduced;

it is desired to bepointed out'that, since the extrem'elower' end' of 'pipe: 3 is substantiallysealed off or. closed, theonlyhigh flow-rate coupling between-fillpipe Sandtheihterior of the tank 11 is byway of'the hydraulic jump arrangement 8'.

Because ofthe energy conversionactionsof the arrangement 8,

there will be some reduction in the maximum rate'of-flow of prising a: hydraulic jump arrangementwhich causesthe falling the liquid through pipe3, and consequentlytsome lengthening in the time required to fill the tank 1. However, it is quite probable that the reduction in water-gasoline mixing (obtained by the use of this invention) will economically balance the lengthened fill time.

As previously stated, the outer conical wall or conical surface of the inverted-funnel member 7 is utilized to substantially seal off (from the tank interior) the lower end of pipe 3. Member 7 comprises part of a means for enabling water to be removed from the tank floor 5. The upper, small-diameter opening of member 7 is sealingly coupled to the lower end of a substantially vertical tube 11 which is mounted concentrically in pipe 3. This concentric mounting is effected at the lower end of tube 11 by means of member 7 (which secured to both tube 11 and pipe 3), and near the upper end of tube 11 by means of a mounting sleeve 15 closely surrounding and secured to tube 11, sleeve 15 being secured to the inner wall of pipe 3 by way of a spider or spoke arrangement 16. The diameter of tube 11 is small compared to that of the fill pipe 3. Tube 1 1 extends from member 7 up to the surface 2 (actually, to a point slightly above the surface), and is closed at its upper end by a removable cap (illustrated as a pivoted closure 12) which is separate from closure 6 and is located somewhat below the latter.

The lower, large-diameter end of the funnellike member 7 is covered by a circular piece 13 of foraminous material (screen) secured around its edge to the inner wall of member 7. The foraminous material 13 excludes solid particles which are larger than a predetermined size from the interior of member 7. The screen 13 is maintained spaced slightly above the tank bottom by means of a plurality of spaced support feet 14 whose upper ends contact the assembly of member 7 and fill pipe 3, and whose lower ends contact the tank bottom 5 It may be seen that the lower end of member 7 (and thus also the lower end of tube 11, which is connected for fluid transmission to the upper end of member 7) opens closely adjacent the tank bottom 5. By connecting the intake or suction of a suitable pump to the upper end of tube 11, the water bottoms may be pumped out of tank 1, whenever desired. The water would pass through screen 13 into the interior of member 7, and thence upwardly through tube 11 to the surface.

One problem which will suggest itself, at least to those skilled in the art to which this invention relates, is the possibility that that portion of fill pipe 3 between member 7 and the jump arrangement 8 will eventually become filled with water, from repeated deliveries into the tank 1. Thereafter, some of this water (albeit a very small amount) would be mixed with the liquid during each delivery into the liquid bulk in tank 1.

The above problem may be obviated by providing several small-diameter weep holes 17 (see FIGS. 4 and 5) in the member 7. These holes would allow the trapped, delivered water to weep down into the water bottoms" layer at the bottom of tank 1. The holes 17 should be sufficiently small in diameter to avoid any substantial flow therethrough (and thus also any substantial mixing, by way of the holes) during delivery (which last-mentioned flow would, of course, bypass the hydraulic jump arrangement 8, and might also cause water to be mixed with the incoming delivery, if the water level in the tank is sufficiently high). The small flow which will occur through holes 17 during delivery would be enough to keep these holes open, preventing them from becoming clogged by dirt.

It is pointed out that, if the level of the water bottoms in the tank is kept below the weep holes 17 (for example, by pumping out the water bottoms" through tube 11, as previously described), even the small mixing problem alluded to in the preceding paragraph would be avoided.

It may be here noted that the combination filling and bottoms-removal arrangement of this invention is inexpensive to construct and install.

Another arrangement for reducing the amount of energy available for mixin at the bottom of the tank 1 (instead of utilizing the hydrau lc ump arrangement 8) would be to load the fill pipe 3 full of an inert packing 'such as large stones, ping-pong balls, etc. In this case, also, viscous friction would use up most of the kinetic energy of the falling liquid. Here, again, there would be some pressure drop, and consequently a decrease in flow rate, but, on the other hand, there would be a reduction in water-gasoline mixing.

Another modification might be to utilize some of the energy of the falling liquid to power a pump which would remove water from the tank bottom (such as a pump which would be connected to the upper end of tube 11). This modification would of course be a more expensive filling arrangement than that disclosed in detail hereinabove, but in the modified arrangement the tank would be cleaned automatically each time a load of gasoline was delivered into the tank.

We claim:

1. In combination with a subterranean storage tank for liquid fuel: a continuous fill pipe extending substantially vertically from the surface to the top of saidtank and thence substantially vertically through the interior of said tank to the bottom thereof, said pipe being coupled to said tank interior near the bottom thereof, the liquid flowing downwardly through said pipe during a tank-filling operation developing a substantial amount of kinetic energy; means cooperating with said pipe for absorbing an appreciable portion of the kinetic energy of said liquid prior to the termination of flow of the liquid from said pipe through said coupling into said tank interior; and a substantially vertical tube, whose diameter is less than that of said pipe, mounted within said pipe, the lower end of said tube opening closely adjacent the bottom of said tank and said tube extending upwardly to the surface.

2. Combination of claim 1, including also a hollow, frustoconical member having its upper, small-diameter end connected for fluid transmission to the lower end of said tube; the lower end of said full pipe being sealed to the outer surface of said member at the lower, large-diameter end of the latter.

3. Combination defined in claim 1, wherein said tube is mounted concentrically in said pipe.

4. Combination defined in claim 1, wherein the lower end of said tube is fastened to the lower end of said fill pipe. 

1. In combination with a subterranean storage tank for liquid fuel: a continuous fill pipe extending substantially vertically from the surface to the top of said tank and thence substantially vertically through the interior of said tank to the bottom thereof, said pipe being coupled to said tank interior near the bottom thereof, the liquid flowing downwardly through said pipe during a tank-filling operation developing a substantial amount of kinetic energy; means cooperating with said pipe for absorbing an appreciable portion of the kinetic energy of said liquid prior to the termination of flow of the liquid from said pipe through said coupling into said tank interior; and a substantially vertical tube, whose diameter is less than that of said pipe, mounted within said pipe, the lower end of said tube opening closely adjacent the bottom of said tank and said tube extending upwardly to the surface.
 2. Combination of claim 1, including also a hollow, frustoconical member having its upper, small-diameter end connected for fluid transmission to the lower end of said tube; the lower end of said full pipe being sealed to the outer surface of said member at the lower, large-diameter end of the latter.
 3. Combination defined in claim 1, wherein said tube is mounted concentrically in said pipe.
 4. Combination defined in claim 1, wherein the lower end of said tube is fastened to the lower end of said fill pipe. 